SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '928e02bfdca3418e5b7bc10d627aec9c4488ed05cb7958b6bb2064a7630a0fd9' 
  AND token = 'YsGIhtMkrBv1MRa87lONNzLLCYc60OSiXTEqPdsTQh0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}